There are known pump lifters used for fuel supply pumps or valve lifters used for valve gears in internal combustion engines such as car engines or the like.
Some of these lifters include a roller at a portion directly contacting a cam lobe provided in fuel supply pumps or valve gear to reduce friction resistance against the cam lobe and to improve wear resistance of the surface contacting the cam lobe (hereinafter referred to as “roller lifter 9”).
The roller lifter 9 is configured, as shown in FIG. 12, with a roller 93 attached to a lifter body 92 having a sliding surface 924 that slides on the inner wall of a cylinder in which the roller lifter 9 is installed. To fabricate the roller lifter, the roller 93 is first placed between a pair of support portions 921 provided to the lifter body 92. An axial support pin 94 of the roller 93 is inserted into support holes 922 formed in the support portions 921, and both ends of the axial support pin 94 are compressed using a hydraulic press or the like to deform the ends to increase their diameters, to mechanically fasten the axial support pin 94 to the support portions 921.
The roller 93 of the roller lifter 9 and the cam lobe are arranged such that their respective rotation axes are parallel, so as to minimize friction resistance between the roller and the cam lobe. For this reason, the lifter body 92 of the roller lifter 9 is formed with an anti-rotation retainer 923 to prevent displacement of the rotation axis of the roller 93, i.e., to prevent the lifter body 92 from rotating relative to the inner wall of the cylinder (see Patent Document 1).
This anti-rotation retainer 923 is formed at one axial end of the lifter body 92 by cutting and bending processes using, for example, a cutting tool or a press. More specifically, the anti-rotation retainer 923 is formed by cutting off part of one end of a cylindrical metal member to form a protruding piece of a predetermined size axially protruding from one end of the lifter body 92, and by bending the protruding piece to protrude radially outward.
The protruding piece needs to be bent largely outward in the radial direction from inside. Therefore, the radial part of the lifter body 92 opposite the protruding piece had to be largely cut off, except for the support portions 921, to form the anti-rotation retainer 923, as shown in FIG. 12.